Use middleware to check if server is running instead of checking PID

Author: vinistock

lib/ruby_lsp/ruby_lsp_rails/rails_client.rb

@@ -38,8 +38,14 @@ def initialize
           MESSAGE
         end
 
-        base_uri = File.read(app_uri_path).chomp
-        @uri = T.let("#{base_uri}/ruby_lsp_rails", String)
+        url = File.read(app_uri_path).chomp
+
+        scheme, rest = url.split("://")
+        uri, port = T.must(rest).split(":")
+
+        @ssl = T.let(scheme == "https", T::Boolean)
+        @uri = T.let(T.must(uri), String)
+        @port = T.let(T.must(port).to_i, Integer)
       end
 
       sig { params(name: String).returns(T.nilable(T::Hash[Symbol, T.untyped])) }
@@ -54,28 +60,22 @@ def model(name)
 
       sig { void }
       def check_if_server_is_running!
-        # Check if the Rails server is running. Warn the user to boot it for Rails features
-        pid_file = ENV.fetch("PIDFILE") { File.join(@root, "tmp", "pids", "server.pid") }
-
-        # If the PID file doesn't exist, then the server hasn't been booted
-        raise ServerNotRunningError, SERVER_NOT_RUNNING_MESSAGE unless File.exist?(pid_file)
-
-        pid = File.read(pid_file).to_i
-
-        begin
-          # Issuing an EXIT signal to an existing process actually doesn't make the server shutdown. But if this
-          # call succeeds, then the server is running. If the PID doesn't exist, Errno::ESRCH is raised
-          Process.kill(T.must(Signal.list["EXIT"]), pid)
-        rescue Errno::ESRCH
-          raise ServerNotRunningError, SERVER_NOT_RUNNING_MESSAGE
-        end
+        request("activate", 0.2)
+      rescue Errno::ECONNREFUSED
+        raise ServerNotRunningError, SERVER_NOT_RUNNING_MESSAGE
+      rescue Net::ReadTimeout
+        # If the server is running, but the initial request is taking too long, we don't want to block the
+        # initialization of the Ruby LSP
       end
 
       private
 
-      sig { params(path: String).returns(Net::HTTPResponse) }
-      def request(path)
-        Net::HTTP.get_response(URI("#{@uri}/#{path}"))
+      sig { params(path: String, timeout: T.nilable(Float)).returns(Net::HTTPResponse) }
+      def request(path, timeout = nil)
+        http = Net::HTTP.new(@uri, @port)
+        http.use_ssl = @ssl
+        http.read_timeout = timeout if timeout
+        http.get("/ruby_lsp_rails/#{path}")
       end
     end
   end

lib/ruby_lsp_rails/middleware.rb

@@ -6,7 +6,7 @@ module Rails
     class Middleware
       extend T::Sig
 
-      PATH_REGEXP = %r{/ruby_lsp_rails/models/(?<model_name>.+)}
+      BASE_PATH = "/ruby_lsp_rails/"
 
       sig { params(app: T.untyped).void }
       def initialize(app)
@@ -16,13 +16,16 @@ def initialize(app)
       sig { params(env: T::Hash[T.untyped, T.untyped]).returns(T::Array[T.untyped]) }
       def call(env)
         request = ActionDispatch::Request.new(env)
-        # TODO: improve the model name regex
-        match = request.path.match(PATH_REGEXP)
+        path = request.path
+        return @app.call(env) unless path.start_with?(BASE_PATH)
 
-        if match
-          resolve_database_info_from_model(match[:model_name])
+        route, argument = path.delete_prefix(BASE_PATH).split("/")
+
+        case route
+        when "models"
+          resolve_database_info_from_model(argument)
         else
-          @app.call(env)
+          [200, { "Content-Type" => "text/plain" }, []]
         end
       rescue
         @app.call(env)

test/ruby_lsp_rails/middleware_test.rb

@@ -34,6 +34,11 @@ class ModelsControllerTest < ActionDispatch::IntegrationTest
         get "/ruby_lsp_rails/models/ApplicationJob"
         assert_response(:not_found)
       end
+
+      test "GET activate returns success to display that server is running" do
+        get "/ruby_lsp_rails/activate"
+        assert_response(:success)
+      end
     end
   end
 end

test/ruby_lsp_rails/rails_client_test.rb

@@ -53,6 +53,14 @@ class RailsClientTest < ActiveSupport::TestCase
       ensure
         ENV["BUNDLE_GEMFILE"] = previous_bundle_gemfile
       end
+
+      test "check_if_server_is_running! raises if no server is found" do
+        Net::HTTP.any_instance.expects(:get).raises(Errno::ECONNREFUSED)
+
+        assert_raises(RailsClient::ServerNotRunningError) do
+          RailsClient.instance.check_if_server_is_running!
+        end
+      end
     end
   end
 end

test/test_helper.rb

@@ -25,7 +25,7 @@ def stub_http_request(code, body)
       response.expects(:code).returns("200")
       response.expects(:body).returns(body)
 
-      Net::HTTP.stubs(:get_response).returns(response)
+      Net::HTTP.any_instance.expects(:get).returns(response)
     end
 
     def setup